package com.lixia.lxframework.framework.utils;

import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 功能描述:
 * <p> 生成验证码工具类
 *
 * @author Mr.wang
 * @date 2017/8/11 15:52
 */
@Component
public class CaptchaUtils {
    private Random random = new Random();
    /**
     * 随机产生的字符串
     */
    private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    /**
     * 图片宽
     */
    private int width = 104;
    /**
     * 图片高
     */
    private int height = 32;
    /**
     * 干扰线数量
     */
    private int lineSize = 40;
    /**
     * 随机产生字符数量
     */
    private int stringNum = 4;

    public CaptchaUtils() {
    }

    /**
     * 获得字体
     */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /**
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * 绘制字符串
     *
     * @param g            产生Image对象的Graphics对象
     * @param randomString 随机数
     * @param i            序号
     * @return
     */
    private String drawString(Graphics2D g, String randomString, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
                .nextInt(121)));
        String rand = String.valueOf(getRandomString(random.nextInt(randString
                .length())));
        randomString += rand;
        g.translate(random.nextInt(3), random.nextInt(3));
        //设置当前字符的x轴坐标
        float x = i * 1.0F * width / 4;
        int y = height / 2 + 7;
        g.drawString(rand, x, y);
        return randomString;
    }

    /**
     * 绘制干扰线
     *
     * @param g
     */
    private void drawLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /**
     * 获取随机的字符
     *
     * @param num
     * @return
     */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }

    /**
     * 生成随机图片
     */
    public String getRandomCode() {
        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        // 产生Image对象的Graphics对象,该对象可以在图像上进行各种绘制操作
        Graphics2D g = (Graphics2D) image.getGraphics();
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
        g.setColor(getRandColor(110, 133));
        // 绘制干扰线
        for (int i = 0; i <= lineSize; i++) {
            drawLine(g);
        }
        // 绘制随机字符
        String randomString = "";
        for (int i = 0; i < stringNum; i++) {
            randomString = drawString(g, randomString, i);
        }
        return randomString;
    }
}
